For Ralph Celidonio, teaching math was never about making things complicated. It was about discipline, practice, patience, and helping students believe they could succeed.
“I always thought math was an easy subject to teach,” he says. “The kids were great. Most of them really were. If they did the work, they did well.”
That belief guided a remarkable 42-year career at Monsignor Bonner Catholic High School, where Ralph taught from 1960 to 2002.
Finding His Way to the Math Classroom
Ralph grew up in Upper Darby and attended St. Alice’s Catholic Grade School before heading to West Catholic High School. Bonner had not yet opened, but it soon became part of the local educational landscape. He later earned his undergraduate degree in English from St. Joseph’s University and completed a master’s degree in educational administration at Temple University.
When Ralph applied for a position at Bonner, he intended to teach English.
“They told me there were no English openings,” he recalls. “But there were nearly 1,000 freshmen entering, because many families were moving out of the city. They needed teachers. I was always good at math, so I asked if there were any math openings, and they said yes.’”
He accepted the role and was assigned five Algebra I classes, each with 52 boys.
“I had more than 260 students that first year,” he says. “And I loved it.”
A Classroom Built on Discipline and Care
Ralph’s classroom style was structured, direct, and deeply supportive.
On the first day of every class, he followed advice from a college professor: wait outside until the bell rang, then enter and slam the door.
“That moment set the tone,” he explains. “You have their complete attention and what you do after that determines your class.”
He clearly outlined expectations and grading:
33 points — Homework
33 points — Quizzes
33 points — Tests
“Homework was the key,” he told his students. “Do it, and you’ll succeed, even if math isn’t your favorite subject.”
Each class began with homework problems worked through on the board, ensuring students understood not just the answers, but the process.
“You can’t put a basketball team on the court without practice,” Ralph says. “Math is the same way.”
Students who needed additional help were always welcome after school.
Beyond the Blackboard
In his early years, Ralph coached baseball and basketball. Noticing the absence of a freshman baseball team, he helped build one from scratch — creating schedules by calling both public and Catholic schools.
“We weren’t very well equipped,” he remembers. “But we made it work.”
Ralph married during his first year at Bonner in a blizzard that closed the school for three days. As his family grew to include five children, he shifted his focus fully to teaching. He and his wife recently celebrated their 65th wedding anniversary.
A Community of Shared Values
Reflecting now on his 42+ years of teaching at Bonner, Ralph says he treasures the continuity of the Bonner community.
“I taught many boys whose parents I went to school with,” he says. “There was a sense of shared values and shared experience.”
For 20 years, he also served as studies director, coordinating student schedules and working closely with teachers and parents.
Among the many colleagues who shaped his experience, Ralph speaks warmly of his best friend, Vince Donohue, a fellow teacher who helped lead Bonner’s Mathletes to diocesan distinction.
He also recalls the impact Father Bill Atkinson had on the Bonner community. “I had him as a student in grade school and coached him for basketball and baseball. I remember the day of his accident vividly. Later he became a priest and returned to teach at Bonner. He had a significant effect on a lot of people - including me.”
“It was a plus-plus environment,” he says. “Teachers inspired other teachers to do better.”
Lessons That Last
Even decades after retiring, Ralph still encounters former students who remember his classroom phrases and lessons.
Recently, one greeted him outside of mass with his famous words: “Take out a half sheet of loose leaf.”
Others recall his emphasis on homework, discipline, and steady practice. “We weren’t there to fail anyone,” Ralph says. “We were there to help them do well.”
Reflecting on his career, he remains characteristically humble. “I just steered the boat,” he says. “The credit belongs to the boys. They made themselves successful.”
More than twenty years after retirement, returning to Bonner still feels like coming home. “I loved it the day I started,” he says. “And I loved it the day I left.”